Integrated Photonic Chip System for Distributed Secure Quantum Information Processing

Abstract

The invention provided is an integrated photonic chip system for distributed secure quantum information processing. This system includes a server integrated photonic quantum chip and a client integrated photonic quantum chip. The server integrated photonic quantum chip includes: a configurable entangled multi-photon source, configured to generate a plurality of photons and respectively output the photons to a server linear optical network and a client linear optical network according to wavelengths; the server linear optical network, configured to prepare an initial state for the photons outputted by a wavelength division multiplexer, perform unitary transformation and linear combination, perform beam combination, and perform projective measurements on the photons that have been subjected to beam combination; and the client integrated photonic quantum chip, configured to transmit the coefficient of linear terms through quantum teleportation, so as to perform linear combination on each item of unitary transformation in the server integrated photonic quantum chip. A server cannot know a specific computation task of a client, but can inform the client of a result through a classical channel after one computation is completed. By using the technical solution of the embodiments of the present disclosure, the computation privacy of the clients is protected.

What is claimed is: 
     
         1 . An integrated photonic chip system for distributed secure quantum information processing, comprising a server integrated photonic quantum chip and a client integrated photonic quantum chip, wherein the server integrated photonic quantum chip and the client integrated photonic quantum chip are connected through a high-dimensional quantum channel;
 the server integrated photonic quantum chip comprises:   a configurable entangled multi-photon source, comprising a configurable optical network, N entangled multi-photon sources, and a wavelength division multiplexer, wherein N is a natural number, and N≥2; by configuring a first phase shifter and a second phase shifter in the interference regulation network to perform interference regulation on a light beam input to the interference regulation network and output a plurality of paths of light, a plurality of path entangled photons are generated by the entangled multi-photon sources; the number of the entangled photons generated by each entangled multi-photon source is recorded as P; and the wavelength division multiplexer is configured to respectively output, according to wavelengths, the plurality of photons outputted by the configurable entangled multi-photon source to a server linear optical network and the client integrated photonic quantum chip;   the server linear optical network comprises:   an initial state preparation linear optical network O, connected to the wavelength division multiplexer, formed into corresponding O 1 , O 2 , . . . , O P-1  according to the wavelengths of the photons outputted by the wavelength division multiplexer, and configured to prepare an initial state for the photons outputted by the configurable entangled multi-photon source;   a unitary operator configuration linear optical network U, correspondingly connected to the initial state preparation linear optical network O, and configured to acquire a linear term coefficient, perform unitary transformation and linear combination, and perform beam combination, recording as U 1   (i) , U 2   (i)  . . . U P-1   (i)  (i=1, 2, . . . N); and   a projective measurement linear optical network T, correspondingly connected to the unitary operator configuration linear optical network U, and configured to perform projective measurement on a photonic quantum state after beam combination, recording as T 1 , T 2 , . . . , T P-1 ; and   the client integrated photonic quantum chip comprises a coefficient configuration linear optical network C, which is connected to the wavelength division multiplexer, and configured to encode paths of the photons outputted by the wavelength division multiplexer, so as to obtain the linear term coefficients, which are recorded as α 1 , α 2 , . . . , α N , and transmit the linear term coefficients through quantum teleportation, to perform linear combination on each item of unitary transformation in the unitary operator configuration linear optical network, so as to obtain a final quantum state result: (Σ i=1   N α i U 1   (i) ⊗U 2   (i) ⊗ . . . U P-1   (i) )O 1 ⊗O 2 ⊗ . . . O P-1 |0 .   
     
     
         2 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the initial state preparation linear optical network, the unitary operator configuration linear optical network, the projective measurement linear optical network, and the coefficient configuration linear optical network all belong to universal linear optical networks. 
     
     
         3 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the configurable entangled multi-photon source, the initial state preparation linear optical network, the unitary operator configuration linear optical network, the projective measurement linear optical network, and the coefficient configuration linear optical network all achieve path encoding through the first phase shifter and the second phase shifter. 
     
     
         4 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the interference regulation network of the configurable entangled multi-photon source comprises a log 2  N-level Mach-Zehnder interferometer, which is arranged in the form of a binary tree, that is, each output port of the previous level Mach-Zehnder interferometer is connected to an input port of the next level Mach-Zehnder interferometer, and a 2 ┌log     2     N┐ th output port of the last level Mach-Zehnder interferometer is connected to a second phase shifter and one entangled multi-photon source; and the Mach-Zehnder interferometer comprises one first phase shifter and two multimode interferometers connected to the first phase shifter. 
     
     
         5 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 4 , wherein the first phase shifter and the second phase shifter adjust each path of light by means of external classical control signals, and enable the phase of each path of light before reaching the configurable entangled multi-photon source to be zero. 
     
     
         6 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the configurable entangled multi-photon source generates the photons with P wavelengths; and the photons with one wavelength are routed to the client integrated photonic quantum chip, and the photons with another P−1 wavelength are respectively correspondingly routed to P−1 groups of initial state preparation linear optical networks, wherein P is a natural number, and P≥2. 
     
     
         7 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the initial state preparation linear optical network comprises a multi-level chain structure. 
     
     
         8 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the unitary operator configuration linear optical network is a triangularly-distributed optical network structure. 
     
     
         9 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the projective measurement linear optical network comprises an inverted tree structure. 
     
     
         10 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 6 , wherein there are N initial state preparation linear optical networks in each of the P−1 groups of initial state preparation linear optical networks; correspondingly, the unitary operator configuration linear optical networks are divided into P−1 groups, and each group has N unitary operator configuration linear optical networks; there are P−1 projective measurement linear optical networks; and each group of unitary operator configuration linear optical networks is correspondingly connected to one group of initial state preparation linear optical networks and one projective measurement linear optical network. 
     
     
         11 . The integrated photonic chip system for distributed secure quantum information processing according to  claim 1 , wherein the coefficient configuration linear optical network in the client integrated photonic quantum chip is a simplified triangularly-distributed optical network structure.